Systems and methods with different utilization of satellite frequency bands by a space-based network and an ancillary terrestrial network

ABSTRACT

A radioterminal communications system includes an ancillary terrestrial component configured to receive from at least some of a plurality of radioterminals using frequencies from a first satellite frequency band (e.g., an L-band) and to transmit to at least some of the plurality of radioterminals using frequencies from a second satellite frequency band (e.g., an S-band). The system further includes a space-based component configured to communicate with the plurality of radioterminals using at least some of the frequencies from the first satellite frequency band and/or at least some of the frequencies from the second satellite frequency band. In some embodiments the ancillary terrestrial component communicates with radioterminals using a Time Division Duplex (TDD) mode and the space-based component communicates with the same or other radioterminals using a Frequency Division Duplex (FDD) and/or a TDD mode.

RELATED APPLICATION

The present invention claims the benefit of U.S. Provisional ApplicationSer. No. 60/561,325 entitled “Different Utilization of SatelliteFrequency Bands By a Space-Based Network and An Ancillary TerrestrialNetwork,” filed Apr. 12, 2004, which is hereby incorporated by referenceherein in its entirety.

FIELD OF THE INVENTION

This invention relates to radioterminal communications systems andmethods, and more particularly to terrestrial cellular and satellitecellular radioterminal communications systems and methods.

BACKGROUND OF THE INVENTION

Satellite radiotelephone communications systems and methods are widelyused for radiotelephone communications. Satellite radiotelephonecommunications systems and methods generally employ at least onespace-based component, such as one or more satellites, that is/areconfigured to wirelessly communicate with a plurality of satelliteradiotelephones.

A satellite radiotelephone communications system or method may utilize asingle satellite antenna beam (antenna pattern) covering an entire areaserved by the system. Alternatively or in combination with the above, incellular satellite radiotelephone communications systems and methods,multiple satellite beams (antenna patterns) are provided, each of whichcan serve distinct geographical areas in the overall service region, tocollectively serve an overall satellite footprint. Thus, a cellulararchitecture similar to that used in conventional terrestrial cellularradiotelephone systems and methods can be implemented in cellularsatellite-based systems and methods. The satellite typicallycommunicates with radiotelephones over a bidirectional communicationspathway, with radiotelephone communications signals being communicatedfrom the satellite to the radiotelephone over a downlink or forwardservice link, and from the radiotelephone to the satellite over anuplink or return service link.

The overall design and operation of cellular satellite radiotelephonesystems and methods are well known to those having skill in the art, andneed not be described further herein. Moreover, as used herein, the term“radiotelephone” includes cellular and/or satellite radiotelephones withor without a multi-line display; Personal Communications System (PCS)terminals that may combine a radiotelephone with data processing,facsimile and/or data communications capabilities; Personal DigitalAssistants (PDA) that can include a radio frequency transceiver and/or apager, Internet/Intranet access, Web browser, organizer, calendar and/ora global positioning system (GPS) receiver; and/or conventional laptopand/or palmtop computers or other appliances, which include a radiofrequency transceiver. A radiotelephone also may be referred to hereinas a “radioterminal”, a “mobile terminal” or simply as a “terminal”. Asused herein, the term(s) “radioterminal,” “radiotelephone,” mobileterminal” and/or “terminal” also include(s) any other radiating userdevice/equipment/source that may have time-varying or fixed geographiccoordinates and/or may be portable, transportable, installed in avehicle (aeronautical, maritime, or land-based) and/or situated and/orconfigured to operate locally and/or in a distributed fashion over oneor more terrestrial and/or extra-terrestrial location(s).

Cellular satellite communications systems and methods may deployhundreds of cells, each of which corresponds to one or more spot beams,over their satellite footprint corresponding to a service area. It willbe understood that large numbers of cells may be generally desirable,since the frequency reuse and the capacity of a cellular satellitecommunications system or method may both increase in direct proportionto the number of cells. Moreover, for a given satellite footprint orservice area, increasing the number of cells may also provide a highergain per cell, which can increase the link robustness and improve thequality of service.

Terrestrial networks can enhance cellular satellite radioterminal systemavailability, efficiency and/or economic viability by terrestriallyreusing at least some of the frequency bands that are allocated tocellular satellite radioterminal systems. In particular, it is knownthat it may be difficult for cellular satellite radioterminal systems toreliably serve densely populated areas, because the satellite signal(s)may be blocked by high-rise structures and/or may not penetrate intobuildings. As a result, the satellite spectrum may be underutilized orunutilized in such areas. The terrestrial reuse of at least some of thesatellite system frequencies can reduce or eliminate this potentialproblem.

Moreover, the capacity of a hybrid system, comprising satellite andterrestrial communications connectivity, may be increased by theintroduction of terrestrial frequency reuse of at least some of thesatellite system frequencies, since terrestrial frequency reuse may bemuch denser than that of a satellite-only system. In fact, capacity maybe enhanced where it may be mostly needed, i.e., in densely populatedurban/industrial/commercial areas. As a result, the overall system maybecome more economically viable, as it may be able to serve moreeffectively and reliably a larger subscriber base.

One example of terrestrial reuse of satellite frequencies is describedin U.S. Pat. No. 5,937,332 to the present inventor Karabinis entitledSatellite Telecommunications Repeaters and Retransmission Methods, thedisclosure of which is hereby incorporated herein by reference in itsentirety as if set forth fully herein. As described therein, satellitetelecommunications repeaters are provided which receive, amplify, andlocally retransmit the downlink signal received from a satellite therebyincreasing the effective downlink margin in the vicinity of thesatellite telecommunications repeaters and allowing an increase in thepenetration of uplink and downlink signals into buildings, foliage,transportation vehicles, and other objects which can reduce link margin.Both portable and non-portable repeaters are provided. See the abstractof U.S. Pat. No. 5,937,332.

Satellite radioterminals for a satellite radioterminal system or methodhaving a terrestrial communications capability by terrestrially reusingat least some of the same satellite frequency band and usingsubstantially the same air interface for both terrestrial and satellitecommunications may be cost effective and/or aesthetically appealing.Conventional dual band/dual mode radioterminal alternatives, such as thewell known Thuraya, Iridium and/or Globalstar dual modesatellite/terrestrial radioterminals, duplicate some components (as aresult of the different frequency bands and/or air interface protocolsbetween satellite and terrestrial communications), which leads toincreased cost, size and/or weight of the radioterminal. See U.S. Pat.No. 6,052,560 to the present inventor Karabinis, entitled SatelliteSystem Utilizing a Plurality of Air Interface Standards and MethodEmploying Same.

Satellite radioterminal communications systems and methods that mayemploy terrestrial reuse of satellite frequencies are described in U.S.Pat. No. 6,684,057 to Karabinis, entitled Systems and Methods forTerrestrial Reuse of Cellular Satellite Frequency Spectrum; andPublished U.S. patent application Nos. U.S. Ser. No. 2003/0054760 toKarabinis, entitled Systems and Methods for Terrestrial Reuse ofCellular Satellite Frequency Spectrum; U.S. Ser. No. 2003/0054761 toKarabinis, entitled Spatial Guardbands for Terrestrial Reuse ofSatellite Frequencies; U.S. Ser. No. 2003/0054814 to Karabinis et al.,entitled Systems and Methods for Monitoring Terrestrially ReusedSatellite Frequencies to Reduce Potential Interference; U.S. Ser. No.2003/0073436 to Karabinis et al., entitled Additional Systems andMethods for Monitoring Terrestrially Reused Satellite Frequencies toReduce Potential Interference; U.S. Ser. No. 2003/0054762 to Karabinis,entitled Multi-Band/Multi-Mode Satellite Radiotelephone CommunicationsSystems and Methods; U.S. Ser. No. 2003/0153267 to Karabinis, entitledWireless Communications Systems and Methods Using Satellite-LinkedRemote Terminal Interface Subsystems; U.S. Ser. No. 2003/0224785 toKarabinis, entitled Systems and Methods for Reducing Satellite FeederLink Bandwidth/Carriers In Cellular Satellite Systems; U.S. Ser. No.2002/0041575 to Karabinis et al., entitled CoordinatedSatellite-Terrestrial Frequency Reuse; U.S. Ser. No. 2002/0090942 toKarabinis et al., entitled Integrated or Autonomous System and Method ofSatellite-Terrestrial Frequency Reuse Using Signal Attenuation and/orBlockage, Dynamic Assignment of Frequencies and/or Hysteresis; U.S. Ser.No. 2003/0068978 to Karabinis et al., entitled Space-Based NetworkArchitectures for Satellite Radiotelephone Systems; U.S. Ser. No.2003/0143949 to Karabinis (now U.S. Pat. No. 6,785,543), entitledFilters for Combined Radiotelephone/GPS Terminals; U.S. Ser. No.2003/0153308 to Karabinis, entitled Staggered Sectorization forTerrestrial Reuse of Satellite Frequencies; and U.S. Ser. No.2003/0054815 to Karabinis, entitled Methods and Systems for ModifyingSatellite Antenna Cell Patterns In Response to Terrestrial Reuse ofSatellite Frequencies, all of which are assigned to the assignee of thepresent invention, the disclosures of all of which are herebyincorporated herein by reference in their entirety as if set forth fullyherein.

Some satellite radioterminal communications systems and methods mayemploy satellites that use multiple bands for communications withradioterminals. For example, U.S. patent application Publication No.U.S. Ser. No. 2003/0054762 to Karabinis, cited above, describessatellite radioterminal systems and communications methods that includea space-based component that is configured to communicate withradioterminals in a satellite footprint that is divided into satellitecells. The space-based component is configured to communicate with afirst radioterminal in a first satellite cell over a first frequencyband and/or a first air interface, and to communicate with a secondradioterminal in the first or a second satellite cell over a secondfrequency band and/or a second air interface. An ancillary terrestrialnetwork also is provided that is configured to communicate terrestriallywith the first radioterminal over substantially the first frequency bandand/or substantially the first air interface, and to communicateterrestrially with the second radioterminal over substantially thesecond frequency band and/or substantially the second air interface. Seethe Abstract of U.S. patent application Publication No. U.S. Ser. No.2003/0054762.

SUMMARY OF THE INVENTION

In some embodiments of the present invention, methods are provided foroperating a radioterminal communications system including a space-basednetwork (SBN), comprising a space-based component (SBC), and anancillary terrestrial network (ATN) comprising one or more ancillaryterrestrial components (ATCs). Communications from at least some of aplurality of radioterminals to the one or more ancillary terrestrialcomponents use frequencies from a first satellite frequency band.Communications from the one or more ancillary terrestrial components toat least some of the plurality of radioterminals use frequencies from asecond satellite frequency band. Communications between the space-basedcomponent and the plurality of radioterminals use at least some of thefrequencies from the first satellite frequency band and/or at least someof the frequencies from the second satellite frequency band. The firstsatellite frequency band may include, for example, a first one of anL-band of frequencies and an S-band of frequencies, and the secondsatellite frequency band may include, for example, a second one of theL-band of frequencies and the S-band of frequencies.

Communicating between the space-based component and the plurality ofradioterminals using at least some of the frequencies from the firstsatellite frequency band and/or at least some of the frequencies fromthe second satellite frequency band may include communicating betweenthe space-based component and first radioterminals over forward linksusing frequencies from the first satellite frequency band and overreturn links using frequencies from the first satellite frequency band,and communicating between the space-based component and secondradioterminals over forward links using frequencies from the secondsatellite frequency band and over return links using frequencies fromthe second satellite frequency band. Communicating from at least some ofa plurality of radioterminals to the one or more ancillary terrestrialcomponents using frequencies from a first satellite frequency band mayinclude communicating from third radioterminals using frequencies fromthe first satellite frequency band. Communicating from the one or moreancillary terrestrial components to at least some of the plurality ofradioterminals using frequencies from a second satellite frequency bandmay include communicating from the one or more ancillary terrestrialcomponents to the third radioterminals using frequencies from the secondsatellite frequency band. The third radioterminals may include at leastone of the first radioterminals and/or at least one of the secondradioterminals.

In further embodiments, communicating between the space-based componentand first radioterminals over forward links using frequencies from thefirst satellite frequency band and over return links using frequenciesfrom the first satellite frequency band may include communicating fromthe space-based component to first ones of the first radioterminalsusing frequencies from the first satellite frequency band, andcommunicating from second ones of the first radioterminals to thespace-based component using frequencies from the first satellitefrequency band. Communicating between the space-based component andsecond radioterminals over forward links using frequencies from thesecond satellite frequency band and over return links using frequenciesfrom the second satellite frequency band may include communicating fromthe space-based component to first ones of the second radioterminalsusing frequencies from the second satellite frequency band andcommunicating from second ones of the second radioterminals to thespace-based component using frequencies from the second satellitefrequency band.

According to other embodiments, communicating between the space-basedcomponent and first radioterminals over forward links using frequenciesfrom the first satellite frequency band and over return links usingfrequencies from the first satellite frequency band may includecommunicating between a first satellite of the SBC and the firstradioterminals over forward links using frequencies from the firstsatellite frequency band and return links using frequencies from thefirst satellite frequency band. Communicating between the space-basedcomponent and second radioterminals over forward links using frequenciesfrom the second satellite frequency band and over return links usingfrequencies from the second satellite frequency band may includecommunicating between a second satellite of the SBC and the secondradioterminals over forward links using frequencies from the secondsatellite frequency band and over return links using frequencies fromthe second satellite frequency band.

In additional embodiments of the present invention, an ancillaryterrestrial network includes a first ancillary terrestrial component anda second ancillary terrestrial component. Communicating from at leastsome of a plurality of radioterminals to the ancillary terrestrialnetwork using frequencies from a first satellite frequency band mayinclude communicating from at least some of the radioterminals to thefirst ancillary terrestrial component using at least one of thefrequencies from the first satellite frequency band. Communicating fromthe ancillary terrestrial network to at least some of the plurality ofradioterminals using frequencies from a second satellite frequency bandmay include communicating from the second ancillary terrestrialcomponent to at least some of the radioterminals using at least one ofthe frequencies from the second satellite frequency band.

Communications from the first ancillary terrestrial component to atleast some of the radioterminals may use at least one of the frequenciesfrom the first satellite frequency band, and communications from atleast some of the radioterminals to the second ancillary terrestrialcomponent may use at least one of the frequencies from the secondsatellite frequency bands. Communications services may be provided toradioterminals using the first and/or second ancillary terrestrialcomponents in a common geographic region or over respective differentgeographic regions. In further embodiments, communications services maybe provided to respective first and/or second classes and/or types ofradioterminals using the first and/or second ancillary terrestrialcomponents.

According to still further embodiments, the ancillary terrestrialnetwork further includes a third ancillary terrestrial component.Communicating from at least some of a plurality of radioterminals to theancillary terrestrial network using frequencies from a first satellitefrequency band may include communicating from at least some of theradioterminals to the third ancillary terrestrial component using atleast one of the frequencies from the first satellite frequency band.Communicating from the ancillary terrestrial network to at least some ofthe plurality of radioterminals using frequencies from a secondsatellite frequency band may include communicating from the thirdancillary terrestrial component to at least some of the radioterminalsusing at least one of the frequencies from the second satellitefrequency band. Communications services may be provided toradioterminals using the first, second and/or third ancillaryterrestrial components in a common geographic region or over respectivedifferent geographic regions. In additional embodiments, communicationsservices may be provided to respective first, second and/or third typesand/or classes of radioterminals using the first, second and/or thirdancillary terrestrial components.

According to additional embodiments of the present invention, methodsare provided for operating a radioterminal communications systemincluding a space-based network, comprising a space-based component, andan ancillary terrestrial network comprising one or more ancillaryterrestrial components. The methods include communicating between theone or more ancillary terrestrial components and at least some of aplurality of radioterminals using frequencies from a first and/or secondsatellite frequency band in a Time Division Duplex (TDD) mode, andcommunicating between the space-based component and at least some of theplurality of radioterminals using frequencies from the first and/orsecond satellite frequency band in a Frequency Division Duplex (FDD)mode and/or a TDD mode. The first satellite frequency band may include afirst one of an L-band of frequencies and an S-band of frequencies andthe second satellite frequency band may include a second one of theL-band of frequencies and the S-band of frequencies.

In some embodiments of the present invention, a radioterminalcommunications system includes an ancillary terrestrialsystem/network/component configured to receive from at least some of aplurality of radioterminals using frequencies from a first satellitefrequency band and to transmit to at least some of the plurality ofradioterminals using frequencies from a second satellite frequency band.The radioterminal communications system further includes a space-basedsystem/network/component configured to communicate with the plurality ofradioterminals using at least some of the frequencies from the firstsatellite frequency band and/or at least some of the frequencies fromthe second satellite frequency band.

The space-based system/network/component may be configured tocommunicate with first radioterminals over forward links usingfrequencies from the first satellite frequency band and over returnlinks using frequencies from the first satellite frequency band and tocommunicate with second radioterminals over forward links usingfrequencies from the second satellite frequency band and over returnlinks using frequencies from the second satellite frequency band. Theancillary terrestrial system/network/component may be configured toreceive from third radioterminals using frequencies from the firstsatellite frequency band and to transmit to the third radioterminalsusing frequencies from the second satellite frequency band.

In further embodiments, the space-based system/network/component isfurther configured to transmit to first ones of the first radioterminalsusing frequencies from the first satellite frequency band and to receivefrom second ones of the first radioterminals using frequencies from thefirst satellite frequency band. The space-based system/network/componentmay be further configured to transmit to first ones of the secondradioterminals using frequencies from the second satellite frequencyband and to receive from second ones of the second radioterminals usingfrequencies from the second satellite frequency band. The space-basedsystem/network/component may also be configured to communicate between afirst satellite of the space-based system/network/component and thefirst radioterminals over forward links using frequencies from the firstsatellite frequency band and over return links using frequencies fromthe first satellite frequency band and to communicate between a secondsatellite of the space-based system/network/component and the secondradioterminals over forward links using frequencies from the secondsatellite frequency band and over return links using frequencies fromthe second satellite frequency band.

The ancillary terrestrial system/network/component may include a firstancillary terrestrial component configured to receive from at least someof the radioterminals using at least one of the frequencies from thefirst satellite frequency band, and a second ancillary terrestrialcomponent configured to transmit to at least some of the radioterminalsusing at least one of the frequencies from the second satellitefrequency band. The ancillary terrestrial system/network/component mayalso include a third ancillary terrestrial component configured toreceive from at least some of the radioterminals using at least one ofthe frequencies from the first satellite frequency band and to transmitto at least some of the radioterminals using at least one of thefrequencies from the second satellite frequency band.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-3 are schematic illustrations of wireless communications systemsand operations thereof according to various embodiments of the presentinvention.

DETAILED DESCRIPTION

The present invention now will be described more fully hereinafter withreference to the accompanying drawings, in which embodiments of theinvention are shown. This invention may, however, be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Likenumbers refer to like elements throughout.

It will be understood that although terms such as first and second maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another element. Thus, a first element below could betermed a second element, and similarly, a second element may be termed afirst element without departing from the teachings of the presentinvention. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items. The symbol“/” is also used as a shorthand notation for “and/or”. Moreover, as usedherein, “substantially the same” band(s) means that two or more bandsbeing compared substantially overlap, but that there may be some areasof non-overlap, for example at a band end. Moreover, “substantially thesame” air interface(s) means that two or more air interfaces beingcompared are similar but need not be identical. Some differences mayexist between the two or more air interfaces to account, for example,for different characteristics between a terrestrial and satelliteenvironment. For example, a different vocoder rate may be used (forexample, approximately 9 to 13 kbps for terrestrial communications andapproximately 2 to 4 kbps for satellite), a different forward errorcorrection coding and/or a different interleaving depth may be usedand/or different spread-spectrum codes.

A satellite radioterminal communications service provider may have ormay acquire a license and/or authority to operate over at least somefrequencies of a first satellite frequency band and over at least somefrequencies of at least a second satellite frequency band. For example,the first satellite frequency band may be an L-band satellite frequencyband and the second satellite frequency band may be an S-band satellitefrequency band. Alternatively or in combination with the above, thesatellite radioterminal communications service provider may have or mayacquire a license and/or authority to operate over a first set offrequencies of a satellite frequency band and over at least a second setof frequencies of the satellite frequency band. As such, the serviceprovider may request and receive regulatory authority to pool/aggregateat least some frequencies from each one of the at least two satellitefrequency bands and/or first and second set of frequencies of thesatellite frequency band and deploy systems and/or methods that may beoperative over the pool/aggregate of the at least some frequencies fromeach of the at least two satellite frequency bands and/or the first andsecond set of frequencies of the satellite frequency band.

Some embodiments of the present invention provide satelliteradioterminal communications systems and methods wherein multiplesatellite frequency bands are used differently by a space-based networkand an ancillary terrestrial network. More specifically, someembodiments of the present invention comprise a Space-Based Network(SBN) and an Ancillary Terrestrial Network (ATN) wherein the SBN and theATN utilize the at least two satellite frequency bands in differentways. The SBN comprises at least one Space-Based Component (SBC), suchas a satellite, that is operative to communicate with at least onesatellite radioterminal over forward and return links of the firstsatellite frequency band and/or over forward and return links of thesecond satellite frequency band. The ATN comprises at least oneAncillary Terrestrial Component (ATC), and is operative to sendinformation from at least one ATC radioterminal to the at least one ATCutilizing at least one frequency of the first satellite frequency band.The ATN is also operative to send information from the at least one ATCto the at least one ATC radioterminal utilizing at least one frequencyof the second satellite frequency band. In sending information from theATC radioterminal to the ATC, the at least one frequency utilized by theATC radioterminal may be a frequency belonging to a forward and/or areturn link of the first satellite frequency band. In sendinginformation from the at least one ATC to the at least one ATCradioterminal, the at least one frequency utilized by the ATC may be afrequency belonging to a forward and/or a return link of the secondsatellite frequency band.

FIGS. 1-3 schematically illustrate satellite radioterminalcommunications systems and methods according to various embodiments ofthe present invention. More specifically, as shown in FIG. 1, aspace-based component, such as a satellite 110, communicates with one ormore radioterminals 120 over a satellite footprint 112. Theradioterminals 120 are also configured to communicate with one or moreATCs 130 of an ATN, wherein the ATN may be geographically spaced apartfrom and/or at least partially overlapping with the satellite footprint112.

Still referring to FIG. 1, the satellite 110 communicates with theradioterminal 120 using forward link frequencies in the first satelliteband (F1) and/or forward link frequencies in the second satellite band(F2), denoted collectively by F1/F2. Also, the radioterminal 120communicates with the satellite 110 using return link frequencies in thefirst satellite band (R1) and/or return link frequencies in the secondsatellite band (R2), collectively referred to as R1/R2.

Terrestrially, the radioterminals 120 transmit communications to one ormore ATCs 130 using substantially the same return link frequencies inthe first satellite band (R1′) and/or substantially the same forwardlink frequencies in the first satellite band (F1′), collectivelyreferred to as R1′/F1′. The ATCs 130 transmit communications to theradioterminals 120 using substantially the same return link frequenciesof the second satellite band (R2′) and/or substantially the same forwardlink frequencies of the second satellite band (F2′), collectivelyreferred to as R2′/F2′.

Thus, the second satellite band, such as the S-band, may be used forforward link communications from the ATC 130 to the radioterminals 120,and the first satellite band, such as the L-band, may be used for returnlink communications from the radioterminals 120 to the ATC 130. Stateddifferently, in some embodiments of the present invention, theradioterminals 120 may not radiate terrestrially for the purpose ofcommunicating with one or more ATCs 130 using frequencies of the secondsatellite band, such as the S-band and/or the ATCs 130 may not radiateterrestrially for the purpose of communicating with one or moreradioterminals 120 using frequencies of the first satellite band, suchas the L-band. Reduced interference potential may thereby be provided insome embodiments of the invention. It will also be understood that theprime (′) notation may also indicate a subset of the unprimed frequencyband, such as at least one frequency of the unprimed frequency band, inother embodiments of the present invention.

FIG. 2 illustrates other embodiments of the present invention, where twotypes of radioterminals 220 a, 220 b are provided that communicate withan ATC 130, and with a satellite 110. As shown in FIG. 2, the satellite110 is configured to communicate with the first type of radioterminals220 a using forward and return link frequencies in the first satelliteband (F1 and R1), and to communicate with the second radioterminals 220b using forward and return link frequencies in the second satellite band(F2 and R2). Both of the radioterminals 220 a and 220 b are configuredto communicate with one or more ATCs 130 using the frequency bands thatwere described above in connection with FIG. 1. Accordingly, in someembodiments of FIG. 2, the radioterminals 220 a and 220 b may notradiate terrestrially for the purpose of communicating with one or moreATCs 130 using frequencies of the second satellite band, such as theS-band and/or the ATCs 130 may not radiate terrestrially for the purposeof communicating with one or more radioterminals 120 a, 120 b usingfrequencies of the first satellite band, such as the L-band.

FIG. 3 illustrates other embodiments of the present invention from theseparate standpoints of SBN operation and ATN operation. SBN operationalso is illustrated relative to the frequencies it uses. Morespecifically, as shown at the top of FIG. 3, a satellite 110communicates with first radioterminals 220 a using a forward linkfrequency from the first satellite band (F1) and a return link frequencyfrom the first satellite band R1, such as the L-band. It is understoodthat the two radioterminals 220 a that are illustrated as separate unitsin FIG. 3 may be the same radioterminal unit. The satellite 110 alsocommunicates with second radioterminals 220 b over a forward linkfrequency (F2) and a return link frequency (R2) from the secondsatellite band, such as S-band. Here, also, it is understood that thetwo radioterminals 220 b that are illustrated as separate units in FIG.3 may be the same radioterminal unit. It is further understood thatinstead of configuring a single satellite, as illustrated in FIGS. 1through 3; to communicate with radioterminals using frequencies of thefirst and/or second satellite frequency band(s), the SBN may comprisetwo or more satellites where at least one satellite is configured tocommunicate with radioterminals using at least some frequencies of thefirst satellite band, such as the L-band, and where at least a secondsatellite is configured to communicate with radioterminals using atleast some frequencies of the second satellite band, such as the S-band.As shown at the bottom of FIG. 3, in ATN operation, an ATN radioterminal220 c, which may be the same or different from radioterminals 220 aand/or 220 b, communicates with an ATC 130 using substantially the firstsatellite band SB1, or at least a portion thereof, for return linkcommunications and substantially the second satellite band SB2, or atleast a portion thereof, for forward link communications. The ATNterminals 220 c therefore do not radiate terrestrially to communicatewith the ATC(s) 130 using frequencies of the second satellite band, suchas the S-band, and the ATC(s) 130 does/do not radiate terrestrially tocommunicate with the radioterminal(s) 220 c using frequencies of thefirst satellite band, such as the L-band, in some embodiments of FIG. 3.

In other embodiments, the ATN may be configured with at least one firstand/or at least one second type of ATC. The at least one first type ofATC may be configured to communicate with at least one radioterminal byradiating at least one frequency of the first satellite band forwardlink(s) and to receive communications from at least one radioterminal byreceiving at least one frequency of the first satellite band returnlink(s). The at least one second type of ATC may be configured tocommunicate with at least one radioterminal by radiating at least onefrequency of the second satellite band forward link(s) and to receivecommunications from at least one radioterminal by receiving at least onefrequency of the second satellite band return link(s). The at least onefirst and the at least one second ATC may be deployed to providecommunications service to radioterminals over a common, substantiallycommon, or different geographic areas.

In still other embodiments, the ATN may be configured with at least onefirst and/or at least one second and/or at least one third type of ATC.The at least one first type of ATC may be configured to communicate withat least one radioterminal by radiating at least one frequency of thefirst satellite band forward link(s) and to receive communications fromat least one radioterminal by receiving at least one frequency of thefirst satellite band return link(s). The at least one second type of ATCmay be configured to communicate with at least one radioterminal byradiating at least one frequency of the second satellite band forwardlink(s) and to receive communications from at least one radioterminal byreceiving at least one frequency of the second satellite band returnlink(s). The at least one third type of ATC may be configured tocommunicate with at least one radioterminal by radiating at least onefrequency of the second satellite band forward and/or return link(s) andto receive communications from at least one radioterminal by receivingat least one frequency of the first satellite band return and/or forwardlink(s). The at least one first, second and/or third ATC may be deployedto provide communications service to radioterminals over a common,substantially common, or different geographic areas. For example, the atleast one first type of ATC may be deployed to provide service toradioterminals in New York, the at least one second type of ATC may bedeployed to provide service to radioterminals in Boston, and the atleast one third type of ATC may be deployed to provide service toradioterminals in Los Angeles. Alternatively, all three ATC types, orany two of the three ATC types may be deployed in the same orsubstantially the same geographic area to provide service to differentclasses/types of radioterminals and/or to one class/type ofradioterminals.

In further embodiments, the ATN may be configured with at least one ATCthat is configured to communicate with at least one radioterminal in aTime Division Duplex (TDD) mode using any set of frequencies of a firstsatellite frequency band and/or a second satellite frequency band. Forexample, such an ATC may communicate with at least some of a pluralityof radioterminals using frequencies from the first and/or secondsatellite frequency band in a TDD mode, while a space-based component isconfigured to communicate with at least some of the plurality ofradioterminals using frequencies from the first and/or second satellitefrequency band in a Frequency Division Duplex (FDD) mode. A SBN, SBC,ATN and/or ATC may be configured to establish preferentialcommunications with radioterminals by using preferentially the firstand/or second satellite frequency band and/or a portion of a satellitefrequency band. The SBN, SBC, ATN and/or ATC may each be configured toselectively reuse frequencies geographically and the SBN, SBC, ATN andATC may each be configured to selectively reuse frequenciesgeographically differently. For a given frequency, the selectivegeographic frequency reuse of the given frequency by the SBN, SBC, ATN,and/or ATC may be the same or different.

In accordance with additional embodiments wherein the ATN and/or atleast one ATC is/are configured to communicate with radioterminals usinga TDD air interface protocol in conjunction with a SBN and/or a SBC thatis/are configured to communicate with the same and/or otherradioterminals using a FDD and/or a TDD air interface protocol(s), theSBN, SBC, ATN, the at least one ATC and/or at least one radioterminalmay be configured and/or responsive to establish preferentialcommunications between the ATN and/or the at least one ATC and theradioterminal over a first geographic area and/or time period and theSBN, SBC, ATN, the at least one ATC and/or at least one radioterminalmay be configured and/or responsive to establish preferentialcommunications between the SBN and/or the SBC and the radioterminal overa second geographic region and/or time period (such as a time periodassociated with an emergency). In further embodiments, the ATN and/or atleast one ATC may be configured to transmit information toradioterminals using a polarization that is substantially orthogonaland/or different relative to a polarization used by the SBN and/or theSBC to communicate with at least some radioterminals. In someembodiments, a radioterminal communicating with the ATN and/or at leastone ATC is configured to radiate and/or receive electromagneticwaveform(s) to/from the ATN and/or the at least one ATC in asubstantially linearly-polarized and/or circularly-polarized spatialorientation(s) using one or more antenna(s) and/or antenna elements thatmay be substantially orthogonally-polarized, differently polarizedand/or spaced apart and the ATN and/or the at least one ATC may beconfigured to receive and process and/or process and transmitinformation from/to the radioterminal using at least two substantiallyorthogonally-polarized antennas and/or antenna elements, differentlypolarized antennas and/or antenna elements and/or spaced-apart antennasand/or antenna elements. In other embodiments, a radioterminal may beconfigured to communicate with the ATN and/or at least one ATC using afirst antenna sub-system, electromagnetic polarization and/or EquivalentIsotropic Radiated Power (EIRP) level of the radioterminal and theradioterminal may further be configured to establish communications witha SBN and/or at least one SBC of the SBN using a second antennasub-system, electro-magnetic polarization and/or EIRP level In someembodiments, the first and second antenna sub-systems, electro-magneticpolarizations and/or EIRP levels are the same and/or identical orsubstantially the same and/or identical; in other embodiments, the firstand second antenna sub-systems, electromagnetic polarizations and/orEIRP levels differ at least partially. In further embodiments, the atleast one ATC is configured to communicate simultaneously with at leasttwo (a first and a second) spaced apart radioterminals in a geographicarea using substantially a common set of frequencies(co-channel/co-frequency communications) and being able to discriminatebetween the communications of the at least two radioterminals by usingat least two antenna patterns that are different in a spatial and/orpolarization orientation.

In the drawings and specification, there have been disclosed exemplaryembodiments of the invention. Although specific terms are employed, theyare used in a generic and descriptive sense only and not for purposes oflimitation, the scope of the invention being defined by the followingclaims.

1. A method of operating a radioterminal communications system includinga space-based network comprising a space-based component and anancillary terrestrial network comprising at least one ancillaryterrestrial component, the method comprising: communicating from atleast some of a plurality of radioterminals to the ancillary terrestrialnetwork using frequencies from a first satellite frequency band;communicating from the ancillary terrestrial network to at least some ofthe plurality of radioterminals using frequencies from a secondsatellite frequency band; and communicating between the space-basedcomponent and the plurality of radioterminals using at least some of thefrequencies from the first satellite frequency band and/or at least someof the frequencies from the second satellite frequency band.
 2. A methodaccording to claim 1: wherein communicating between the space-basedcomponent and the plurality of radioterminals using at least some of thefrequencies from the first satellite frequency band and/or at least someof the frequencies from the second satellite frequency band comprises:communicating between the space-based component and first radioterminalsover forward links using frequencies from the first satellite frequencyband and over return links using frequencies from the first satellitefrequency band; and communicating between the space-based component andsecond radioterminals over forward links using frequencies from thesecond satellite frequency band and over return links using frequenciesfrom the second satellite frequency band; wherein communicating from atleast some of a plurality of radioterminals to the ancillary terrestrialnetwork using frequencies from a first satellite frequency bandcomprises communicating from third radioterminals using frequencies fromthe first satellite frequency band; and wherein communicating from theancillary terrestrial network to at least some of the plurality ofradioterminals using frequencies from a second satellite frequency bandcomprises communicating from the ancillary terrestrial network to thethird radioterminals using frequencies from the second satellitefrequency band.
 3. A method according to claim 2, wherein the thirdradioterminals comprise at least one of the first radioterminals and/orat least one of the second radioterminals.
 4. A method according toclaim 2, wherein communicating between the space-based component andfirst radioterminals over forward links using frequencies from the firstsatellite frequency band and over return links using frequencies fromthe first satellite frequency band comprises: communicating from thespace-based component to first ones of the first radioterminals usingfrequencies from the first satellite frequency band; and communicatingfrom second ones of the first radioterminals to the space-basedcomponent using frequencies from the first satellite frequency band. 5.A method according to claim 2, wherein communicating between thespace-based component and second radioterminals over forward links usingfrequencies from the second satellite frequency band and over returnlinks using frequencies from the second satellite frequency bandcomprises: communicating from the space-based component to first ones ofthe second radioterminals using frequencies from the second satellitefrequency band; and communicating from second ones of the secondradioterminals to the space-based component using frequencies from thesecond satellite frequency band.
 6. A method according to claim 2:wherein communicating between the space-based component and firstradioterminals over forward links using frequencies from the firstsatellite frequency band and over return links using frequencies fromthe first satellite frequency band comprises communicating between afirst satellite and the first radioterminals over forward links usingfrequencies from the first satellite frequency band and return linksusing frequencies from the first satellite frequency band; and whereincommunicating between the space-based component and secondradioterminals over forward links using frequencies from the secondsatellite frequency band and over return links using frequencies fromthe second satellite frequency band comprises communicating between asecond satellite and the second radioterminals over forward links usingfrequencies from the second satellite frequency band and over returnlinks using frequencies from the second satellite frequency band.
 7. Amethod according to claim 1, wherein the first satellite frequency bandcomprises a first one of an L-band of frequencies and an S-band offrequencies and wherein the second satellite frequency band comprises asecond one of the L-band of frequencies and the S-band of frequencies.8. A method according to claim 1: wherein the ancillary terrestrialnetwork comprises a first ancillary terrestrial component and a secondancillary terrestrial component; wherein communicating from at leastsome of a plurality of radioterminals to the ancillary terrestrialnetwork using frequencies from a first satellite frequency bandcomprises communicating from at least some of the radioterminals to thefirst ancillary terrestrial component using at least one of thefrequencies from the first satellite frequency band; and whereincommunicating from the ancillary terrestrial network to at least some ofthe plurality of radioterminals using frequencies from a secondsatellite frequency band comprises communicating from the secondancillary terrestrial component to at least some of the radioterminalsusing at least one of the frequencies from the second satellitefrequency band.
 9. A method according to claim 8, further comprising:communicating from the first ancillary terrestrial component to at leastsome of the radioterminals using at least one of the frequencies fromthe first satellite frequency band; and communicating from at least someof the radioterminals to the second ancillary terrestrial componentusing at least one of the frequencies from the second satellitefrequency bands.
 10. A method according to claim 9, further comprisingproviding communications services to radioterminals using the first andsecond ancillary terrestrial components in a common geographic region orover respective different geographic regions and wherein the first andsecond ancillary terrestrial components are mechanically and/orelectrically separate ancillary terrestrial components that aresubstantially co-located or spaced apart or are at least partiallyintegrated mechanically and/or electrically into one ancillaryterrestrial component and are substantially co-located.
 11. A methodaccording to claim 9, further comprising providing communicationsservices to respective first and second classes and/or types ofradioterminals using the first and second ancillary terrestrialcomponents.
 12. A method according to claim 8: wherein the ancillaryterrestrial network further comprises a third ancillary terrestrialcomponent; wherein communicating from at least some of a plurality ofradioterminals to the ancillary terrestrial network using frequenciesfrom a first satellite frequency band comprises communicating from atleast some of the radioterminals to the third ancillary terrestrialcomponent using at least one of the frequencies from the first satellitefrequency band; and wherein communicating from the ancillary terrestrialnetwork to at least some of the plurality of radioterminals usingfrequencies from a second satellite frequency band comprisescommunicating from the third ancillary terrestrial component to at leastsome of the radioterminals using at least one of the frequencies fromthe second satellite frequency band.
 13. A method according to claim 12,further comprising providing communications services to radioterminalsusing the first, second and/or third ancillary terrestrial components ina common geographic region or over respective different geographicregions and wherein the first, second and/or third ancillary terrestrialcomponents are mechanically and/or electrically separate ancillaryterrestrial components that are substantially co-located or spaced apartor are at least partially integrated mechanically and/or electricallyinto one ancillary terrestrial component and are substantiallyco-located.
 14. A method according to claim 12, further comprisingproviding communications services to respective first, second and/orthird types and/or classes of radioterminals using the first, secondand/or third ancillary terrestrial components.
 15. A method of operatinga radioterminal communications system including a space-based networkcomprising a space-based component and an ancillary terrestrial networkcomprising at least one ancillary terrestrial component, the methodcomprising: communicating between the ancillary terrestrial networkand/or at least one ancillary terrestrial component and at least some ofa plurality of radioterminals using frequencies from a first and/orsecond satellite frequency band in a Time Division Duplex (TDD) mode;and communicating between the space-based network and/or space-basedcomponent and at least some of the plurality of radioterminals usingfrequencies from the first and/or second satellite frequency band in aFrequency Division Duplex (FDD) mode and/or TDD mode.
 16. A methodaccording to claim 15, wherein the first satellite frequency bandcomprises a first one of an L-band of frequencies and an S-band offrequencies and wherein the second satellite frequency band comprises asecond one of the L-band of frequencies and the S-band of frequencies.17. A radioterminal communications system comprising: an ancillaryterrestrial network comprising at least one ancillary terrestrialcomponent configured to receive from at least some of a plurality ofradioterminals using frequencies from a first satellite frequency bandand to transmit to at least some of the plurality of radioterminalsusing frequencies from a second satellite frequency band; and aspace-based network comprising a space-based component configured tocommunicate with the plurality of radioterminals using at least some ofthe frequencies from the first satellite frequency band and/or at leastsome of the frequencies from the second satellite frequency band.
 18. Asystem according to claim 17: wherein the space-based component isconfigured to communicate with first radioterminals over forward linksusing frequencies from the first satellite frequency band and overreturn links using frequencies from the first satellite frequency bandand to communicate with second radioterminals over forward links usingfrequencies from the second satellite frequency band and over returnlinks using frequencies from the second satellite frequency band; andwherein the at least one ancillary terrestrial component is configuredto receive from third radioterminals using frequencies from the firstsatellite frequency band and to transmit to the third radioterminalsusing frequencies from the second satellite frequency band.
 19. A systemaccording to claim 18, wherein the third radioterminals comprise atleast one of the first radioterminals and/or at least one of the secondradioterminals.
 20. A system according to claim 18, wherein thespace-based component is further configured to transmit to first ones ofthe first radioterminals using frequencies from the first satellitefrequency band and to receive from second ones of the firstradioterminals using frequencies from the first satellite frequencyband.
 21. A system according to claim 18, wherein the space-basedcomponent is further configured to transmit to first ones of the secondradioterminals using frequencies from the second satellite frequencyband and to receive from second ones of the second radioterminals usingfrequencies from the second satellite frequency band.
 22. A systemaccording to claim 18, wherein the space-based component is furtherconfigured to communicate between a first satellite and the firstradioterminals over forward links using frequencies from the firstsatellite frequency band and over return links using frequencies fromthe first satellite frequency band and to communicate between a secondsatellite and the second radioterminals over forward links usingfrequencies from the second satellite frequency band and over returnlinks using frequencies from the second satellite frequency band.
 23. Asystem according to claim 17, wherein the first satellite frequency bandcomprises a first one of an L-band of frequencies and an S-band offrequencies and wherein the second satellite frequency band comprises asecond one of the L-band of frequencies and the S-band of frequencies.24. A system according to claim 17, wherein the ancillary terrestrialnetwork comprises: a first ancillary terrestrial component configured toreceive from at least some of the radioterminals using at least one ofthe frequencies from the first satellite frequency band; and a secondancillary terrestrial component configured to transmit to at least someof the radioterminals using at least one of the frequencies from thesecond satellite frequency band.
 25. A system according to claim 24:wherein the first ancillary terrestrial component is further configuredto transmit to at least some of the radioterminals using at least one ofthe frequencies from the first satellite frequency band; and wherein thesecond ancillary terrestrial component is further configured to receivefrom at least some of the radioterminals using at least one of thefrequencies from the second satellite frequency bands.
 26. A systemaccording to claim 25, wherein the first and second ancillaryterrestrial components are configured to provide communications servicesto radioterminals in a common geographic region or over respectivedifferent geographic regions and wherein the first and second ancillaryterrestrial components are mechanically and/or electrically separateancillary terrestrial components that are substantially co-located orspaced apart or are at least partially integrated mechanically and/orelectrically into one ancillary terrestrial component and aresubstantially co-located.
 27. A system according to claim 25, whereinthe first and second ancillary terrestrial components are configured toprovide communications services to respective first and second classesand/or types of radioterminals.
 28. A system according to claim 24,wherein the ancillary terrestrial network further comprises a thirdancillary terrestrial component configured to receive from at least someof the radioterminals using at least one of the frequencies from thefirst satellite frequency band and to transmit to at least some of theradioterminals using at least one of the frequencies from the secondsatellite frequency band.
 29. A system according to claim 28, whereinthe first, second and/or third ancillary terrestrial components areconfigured to provide communications services to radioterminals in acommon geographic region or over respective different geographic regionsand wherein the first, second and/or third ancillary terrestrialcomponents are mechanically and/or electrically separate ancillaryterrestrial components that are substantially co-located or spaced apartor are at least partially integrated mechanically and/or electricallyinto one ancillary terrestrial component and are substantiallyco-located.
 30. A system according to claim 28, wherein the first,second and/or third ancillary terrestrial components are configured toprovide communications services to respective first, second and/or thirdtypes and/or classes of radioterminals.
 31. A radioterminalcommunications system comprising: an ancillary terrestrial networkcomprising at least one ancillary terrestrial component configured tocommunicate with at least some of a plurality of radioterminals usingfrequencies from a first and/or second satellite frequency band in aTime Division Duplex (TDD) mode; and a space-based network comprising aspace-based component configured to communicate with at least some ofthe plurality of radioterminals using frequencies from the first and/orsecond satellite frequency band in a Frequency Division Duplex (FDD)and/or TDD mode.
 32. A system according to claim 31, wherein the firstsatellite frequency band comprises a first one of an L-band offrequencies and an S-band of frequencies and wherein the secondsatellite frequency band comprises a second one of the L-band offrequencies and the S-band of frequencies.
 33. A radioterminalcommunications system according to claim 31 wherein the at least oneancillary terrestrial component is further configured to preferentiallycommunicate with at least some of the plurality of radioterminals usingfrequencies from a first and/or second satellite frequency band in aTime Division Duplex (TDD) mode over a first geographic area and/orwherein the space-based component is further configured topreferentially communicate with at least some of the plurality ofradioterminals using frequencies from the first and/or second satellitefrequency band in a Frequency Division Duplex (FDD) and/or TDD mode overa second geographic area.
 34. An ancillary terrestrial componentconfigured to receive from at least some of a plurality ofradioterminals using frequencies from a first satellite frequency bandand to transmit to at least some of the plurality of radioterminalsusing frequencies from a second satellite frequency band, wherein theancillary terrestrial component is configured for use in conjunctionwith a space-based component that communicates with the plurality ofradioterminals using at least some of the frequencies from the firstsatellite frequency band and/or at least some of the frequencies fromthe second satellite frequency band.
 35. An ancillary terrestrialcomponent according to claim 34, wherein the space-based system isconfigured to communicate with first radioterminals over forward linksusing frequencies from the first satellite frequency band and overreturn links using frequencies from the first satellite frequency bandand to communicate with second radioterminals over forward links usingfrequencies from the second satellite frequency band and over returnlinks using frequencies from the second satellite frequency band, andwherein the ancillary terrestrial component is configured to receivefrom third radioterminals using frequencies from the first satellitefrequency band and to transmit to the third radioterminals usingfrequencies from the second satellite frequency band.
 36. An ancillaryterrestrial component according to claim 35, wherein the thirdradioterminals comprise at least one of the first radioterminals and/orat least one of the second radioterminals.
 37. An ancillary terrestrialcomponent according to claim 34, wherein the first satellite frequencyband comprises a first one of an L-band of frequencies and an S-band offrequencies and wherein the second satellite frequency band comprises asecond one of the L-band of frequencies and the S-band of frequencies.38. An ancillary terrestrial component according to claim 34, furthercomprising: a first ancillary terrestrial component configured toreceive from at least some of the radioterminals using at least one ofthe frequencies from the first satellite frequency band; and a secondancillary terrestrial component configured to transmit to at least someof the radioterminals using at least one of the frequencies from thesecond satellite frequency band.
 39. An ancillary terrestrial componentaccording to claim 38: wherein the first ancillary terrestrial componentis further configured to transmit to at least some of the radioterminalsusing at least one of the frequencies from the first satellite frequencyband; and wherein the second ancillary terrestrial component is furtherconfigured to receive from at least some of the radioterminals using atleast one of the frequencies from the second satellite frequency bands.40. An ancillary terrestrial component according to claim 39, whereinthe first and second ancillary terrestrial components are configured toprovide communications services to radioterminals in a common geographicregion or over respective different geographic regions and wherein thefirst and second ancillary terrestrial components are mechanicallyand/or electrically separate ancillary terrestrial components that aresubstantially co-located or spaced apart or are at least partiallyintegrated mechanically and/or electrically into one ancillaryterrestrial component and are substantially-co-located.
 41. An ancillaryterrestrial component according to claim 39, wherein the first andsecond ancillary terrestrial components are configured to providecommunications services to respective first and second classes and/ortypes of radioterminals.
 42. An ancillary terrestrial componentaccording to claim 38, further comprising a third ancillary terrestrialcomponent configured to receive from at least some of the radioterminalsusing at least one of the frequencies from the first satellite frequencyband and to transmit to at least some of the radioterminals using atleast one of the frequencies from the second satellite frequency band.43. An ancillary terrestrial component according to claim 42, whereinthe first, second and/or third ancillary terrestrial components areconfigured to provide communications services to radioterminals in acommon geographic region or over respective different geographic regionsand wherein the first, second and/or third ancillary terrestrialcomponents are mechanically and/or electrically separate ancillaryterrestrial components that are substantially co-located or spaced apartor are at least partially integrated mechanically and/or electricallyinto one ancillary terrestrial component and are substantiallyco-located.
 44. An ancillary terrestrial component according to claim42, wherein the first, second and/or third ancillary terrestrialcomponents are configured to provide communications services torespective first, second and/or third types and/or classes ofradioterminals.
 45. A spaced based component configured for use inconjunction with an ancillary terrestrial component that receives fromat least some of a plurality of radioterminals using frequencies from afirst satellite frequency band and transmits to at least some of theplurality of radioterminals using frequencies from a second satellitefrequency band, the space-based component configured to communicate withthe plurality of radioterminals using at least some of the frequenciesfrom the first satellite frequency band and/or at least some of thefrequencies from the second satellite frequency band.
 46. A space-basedcomponent according to claim 45, further configured to communicate withfirst radioterminals over forward links using frequencies from the firstsatellite frequency band and over return links using frequencies fromthe first satellite frequency band and to communicate with secondradioterminals over forward links using frequencies from the secondsatellite frequency band and over return links using frequencies fromthe second satellite frequency band.
 47. A space-based componentaccording to claim 46, further configured to transmit to first ones ofthe first radioterminals using frequencies from the first satellitefrequency band and to receive from second ones of the firstradioterminals using frequencies from the first satellite frequencyband.
 48. A space-based component according to claim 46, furtherconfigured to transmit to first ones of the second radioterminals usingfrequencies from the second satellite frequency band and to receive fromsecond ones of the second radioterminals using frequencies from thesecond satellite frequency band.
 49. A space-based component accordingto claim 46, further configured to communicate between a first satelliteand the first radioterminals over forward links using frequencies fromthe first satellite frequency band and return links using frequenciesfrom the first satellite frequency band and to communicate between asecond satellite and the second radioterminals over forward links usingfrequencies from the second satellite frequency band and over returnlinks using frequencies from the second satellite frequency band.
 50. Aspace-based component according to claim 45, wherein the first satellitefrequency band comprises a first one of an L-band of frequencies and anS-band of frequencies and wherein the second satellite frequency bandcomprises a second one of the L-band of frequencies and the S-band offrequencies.
 51. An ancillary terrestrial network and/or an ancillaryterrestrial component configured to communicate with at least some of aplurality of radioterminals using frequencies from a first and/or secondsatellite frequency band in a Time Division Duplex (TDD) mode inconjunction with a space-based network and/or a space-based componentconfigured to communicate with at least some of the plurality ofradioterminals using frequencies from the first and/or second satellitefrequency band(s) in a Frequency Division Duplex (FDD) and/or TDD mode.52. An ancillary terrestrial network and/or an ancillary terrestrialcomponent according to claim 51, wherein the first satellite frequencyband comprises a first one of an L-band of frequencies and an S-band offrequencies and wherein the second satellite frequency band comprises asecond one of the L-band of frequencies and the S-band of frequencies.53. An ancillary terrestrial network and/or an ancillary terrestrialcomponent according to claim 51, wherein the first satellite frequencyband comprises a first set of frequencies of an L-band and/or an S-bandand wherein the second satellite frequency band comprises a second setof frequencies of the L-band and/or the S-band.
 54. An ancillaryterrestrial network and/or an ancillary terrestrial component accordingto claim 51 wherein the ancillary terrestrial network and/or theancillary terrestrial component communicates/communicate substantiallyco-frequency and/or co-channel with at least a first and secondradioterminal over a geographic area using at least a first and secondradiation and/or antenna pattern, respectively, that differ in a spatialand/or polarization orientation.
 55. An ancillary terrestrial networkand/or an ancillary terrestrial component according to claim 50 whereinthe ancillary terrestrial network and/or the ancillary terrestrialcomponent communicate with radioterminals using two or moresubstantially orthogonally-polarized antennas and/or antenna elements,differently polarized antennas and/or antenna elements and/orspaced-apart antennas and/or antenna elements.
 56. A radioterminalconfigured to communicate with an ancillary terrestrial network and/oran ancillary terrestrial component using frequencies from a first and/orsecond satellite frequency band in a Time Division Duplex (TDD) mode andto communicate with a space-based network and/or a space-based componentusing frequencies from the first and/or second satellite frequencyband(s) in a Frequency Division Duplex (FDD) and/or TDD mode.
 57. Aradioterminal according to claim 56, wherein the first satellitefrequency band comprises a first one of an L-band of frequencies and anS-band of frequencies and wherein the second satellite frequency bandcomprises a second one of the L-band of frequencies and the S-band offrequencies.
 58. A radioterminal according to claim 56, wherein thefirst satellite frequency band comprises a first set of frequencies ofan L-band and/or an S-band and wherein the second satellite frequencyband comprises a second set of frequencies of the L-band and/or theS-band.
 59. A radioterminal according to claim 56 wherein theradioterminal is further configured to preferentially communicate withthe ancillary terrestrial network and/or the ancillary terrestrialcomponent using frequencies from a first and/or second satellitefrequency band in a Time Division Duplex (TDD) mode over a firstgeographic area and/or to preferentially communicate with thespace-based network and/or the space-based component using frequenciesfrom the first and/or second satellite frequency band in a FrequencyDivision Duplex (FDD) and/or TDD mode over a second geographic area. 60.A radioterminal according to claim 56 wherein the radioterminal isfurther configured to communicate with the ancillary terrestrial networkand/or the ancillary terrestrial component and to radiate and/or receiveelectro-magnetic waveform(s) to/from the ancillary terrestrial networkand/or the ancillary terrestrial component in a substantiallylinearly-polarized spatial orientation.